A television documentary is set to bring the debate on speaking and listening difficulties among the under-5s to a mainstream audience on Monday evening.
"Lost for Words", which will be shown as part of the Tonight series, will focus on the belief that up to half of children are entering primary school without being able to speak properly. The statistic was publicised earlier this year by the Bercow Report on services for young people with speech, language and communication needs.
The programme makers spent four weeks trailing two families - one with a two-year-old and one with a four-year-old - as they were encouraged to help their children develop speaking skills.
Angie Mason, the producer, said: "More and more children seem to be appearing at primary school with very poor communication skills. We've been digging around and going back to basics to find out why it is so important that children are spoken to."
Teachers, concerned that children are now entering school unable to string a sentence together, have been at the forefront of the call for change.
Mrs Mason said: "Over a relatively short period of four weeks we see what happens as parents are supported in talking to their children and their children's language takes off. We found it wasn't just in disadvantaged areas, but children from middle class families also had delayed speech.
"We're not laying blame on any particular group; this is a societal problem," she added.
The Bercow review emphasised that it was essential speech and language difficulties are picked up early. It recommended that Sir Jim Rose - his 2006 review of the teaching of early reading already called for speaking and listening to get much greater priority - examine how to strengthen the focus on communication in the forthcoming primary curriculum review.
The Government's response included the Pounds 40 million Every Child a Talker programme, which will train nursery staff in supporting speech. "Lost for Words" also features research on buggies from the Talk to Your Baby campaign. The study, funded by the Sutton Trust, found that mothers talk twice as much to their babies if they are in buggies which face them rather than looking ahead.
Talk to Your Baby was launched by the National Literacy Trust after a joint survey with the National Association of Head Teachers in 2001 found 75 per cent of nursery and primary heads were concerned there had been a significant decline in children's ability to speak when they started school.
In 2003, Alan Wells, then director of the Basic Skills Agency, said children were being damaged by having little more communication than a "daily grunt", and David Bell, then head of Ofsted, also raised fears that children's verbal skills were at an all time low.
Now schools are being urged to help parents of pupils who have young siblings to boost their speaking skills before they go to nursery.
Liz Attenborough, director of the Talk to Your Baby campaign, said primary teachers and heads were ideally placed to talk to parents about the importance of communicating with babies.
Tonight: "Lost For Words", Monday November 24, 8pm on ITV1.